Ok my question this time is that im looking to buy a cylinder kit from esr for my 1985 250r. I dont know if i should get the power valve kit or the regular kit, and the 350 or the 370. Is the power valve way better and worth the extra money, what exactly does it do, and as far as the 350 or 370 kit if i get the power valve, I have a 38 mm carb and an fmf fatty pipe with a power core silencer, im running the air box elimanator, and i have the cr250 reeds, i have a plus 3 swing arm and plus 4 rear axle, and i was just wondering if the 370 is too big for my set up, for instance if id need a bigger carb, and my next question will be with the 350 or 370 what sprockets should i run for dunning, I guess i should have stated earlier that all my recomendations should be for dune riding cause thats what i do, comp hill, razor hopping, and hill shooting, i want an all around dune beast, and finally the most important question, jk, but how will the 350 or 370 do against yfz and such when i race, thanks guys

 

It is my understanding that the big bore trikes don't dune very well, they are mostly for straight drags. I think you will need at least a 40mm carb. I run 13/39 sprockets and they do great duning and drag racing. A 350 or 370 will kill a 450. Hell you could go with the ESR bolton 330 kit and most likely beat them. I would change your pipe to the ESR ATC 5 pipe. I don't know anything about the power valve. I would PM 344PV for info on that. Just my .02